We have systematically investigated the energetics and stability of Ag atom in 3CSiC with various charge states using first-principles calculations within large supercells. Up to 18 Ag-defect configurations have been examined, including substitutionals, interstitials, and vacancy-based complexes. A general trend is that the formation energy of Ag-defect complexes is generally lower than interstitial typed defects. With the lowest formation energy, the configuration with Ag_T_Si-V_C³⁺ turns out to be the most stable one. It has also been found a neutral Ag is more likely to substitute a silicon lattice site with a nearest carbon vacancy, thus forming an Ag_Si-V_C pair. All these data are important inputs in the next coarser-level modeling to understand the Ag migration in and release from 3CSiC under both thermal and radiation conditions.

我们已经使用大型超级电池内的第一性原理系统地研究了具有各种电荷状态的3C SiC中Ag原子的能量和稳定性。已检查了多达18种Ag缺陷配置，包括取代基，间隙和基于空位的复合物。一个普遍的趋势是，银缺陷复合物的形成能通常低于填隙型缺陷。以最低的形成能，采用Ag_T _Si -V _C ³⁺的配置被证明是最稳定的配置。还发现中性Ag更有可能用最接近的碳空位代替硅晶格位点，从而形成Ag _Si -V _C一对。所有这些数据都是下一步粗略建模的重要输入，以了解在热和辐射条件下，Ag在3C SiC中的迁移和释放。